Heating, ventilation and air conditioning (HVAC) valves are typically actuated by an electric-motor-driven actuator. In order to enable a precisely defined setting of the valve to be assigned in such applications to a specific position of the actuator, which is an indispensable requirement for precise activation or regulation of the valve, the relative position between actuator and valve must be precisely defined. It is important to bear in mind in this case that a typical HVAC installation has a plurality of controllable valves and that often during the installation or maintenance of an HVAC system the installer responsible does not work with the greatest of care at all times.